The recent studies by [1]} and [2]} picture the morphological diversity of the ALPINE sample at \(z=\)  4–6. Specifically, next to the approximately \(40\%\)  interacting galaxies, about \(30\%\)  are classified as dispersion-dominated systems and about \(\sim \)\(15\%\)  are found to be rotators. The rotators are of special interest as they provide constraints on the dark matter mass of galaxies and also suggest recent relatively smooth mass growth in a cold-gas-accretion-dominated scenario.
Rotators have been characterized at \(z<4\) mainly through Integral Field Unit (IFU) observations of the H\(\alpha \)  emission line (e.g., [3]}, [4]}, [5]}), but also via C\(^+\)  emission for a handful of bright starburst and quasars at higher redshifts (e.g., [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}). Next to a main-sequence galaxy at \(z=4.2\)  [13]} and two galaxies at \(z>6\)  [14]}, [15]}, the ALPINE sample complements these studies with typical main-sequence galaxies at \(z=\)  4–6.
Within the ALPINE sample, [2]} find rotators with rotational velocities between 50–250 km/s and extended rotational structures commonly less than \(7\,{\rm kpc}\)  (although some out to \(\sim \)\(10\,{\rm kpc}\) ) (see also [17]}). The flattening of the rotation curves at a radius of \(\sim \) 1–2 kpc suggest dominating baryon fractions over dark matter. However, strong conclusions cannot be drawn because of insufficient spatial resolution of the ALMA observations. A spatial resolution of at least \(\sim \)\(1\,{\rm kpc}\)  (or 0.1–0.2\(^{\prime \prime }\) ) at a high sensitivity out to large radii (\(\sim \) 7–10 kpc) is necessary for definite answers (see Figure 7 in [2]}).
